First, welcome to the forum- When you get a chance, drop by the intro section and say howdy.
I'll betcha a beer if you look REAL close at that circle, you have the letters ELG. Unfortunately that is not the maker. That is the mark of the government proof house in Liege Belgium. After a gun was made in Belgium, makers shipped them to the proof house. They would be test fired, and marked with a stamp to show they passed. Fine Twist will mean a form of Damascus (twist) steel barrel.
Pictures posted here may help- as will any marking on the gun. To be blunt- expensive guns had the makers names PROMINENTLY displayed. There were boatloads of inexpensive Belgian shotguns made for export- usually to the US. If you have not done so, please use a ramrod and check that it is not loaded. A surprising number of older muzzleloading guns are found still loaded- ran across one 6 months ago, being proudly carried by new owner- had been loaded for over 80 years.
What we have here is... failure- to communicate.